devirtualize-virtual-function-calls.cpp
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// RUN: %clang_cc1 -std=c++98 %s -triple armv7-none-eabi -emit-llvm -o - | FileCheck %s
// RUN: %clang_cc1 -std=c++11 %s -triple armv7-none-eabi -emit-llvm -o - | FileCheck %s
// RUN: %clang_cc1 -std=c++1z %s -triple armv7-none-eabi -emit-llvm -o - | FileCheck %s
struct A {
virtual void f();
virtual void f_const() const;
virtual void g();
A h();
};
A g();
void f(A a, A *ap, A& ar) {
// This should not be a virtual function call.
// CHECK: call void @_ZN1A1fEv(%struct.A* %a)
a.f();
// CHECK: call void %
ap->f();
// CHECK: call void %
ar.f();
// CHECK: call void @_ZN1A1fEv
A().f();
// CHECK: call void @_ZN1A1fEv
g().f();
// CHECK: call void @_ZN1A1fEv
a.h().f();
// CHECK: call void @_ZNK1A7f_constEv
a.f_const();
// CHECK: call void @_ZN1A1fEv
(a).f();
}
struct D : A { virtual void g(); };
struct XD { D d; };
D gd();
void fd(D d, XD xd, D *p) {
// CHECK: call void @_ZN1A1fEv(%struct.A*
d.f();
// CHECK: call void @_ZN1D1gEv(%struct.D*
d.g();
// CHECK: call void @_ZN1A1fEv
D().f();
// CHECK: call void @_ZN1D1gEv
D().g();
// CHECK: call void @_ZN1A1fEv
gd().f();
// CHECK: call void @_ZNK1A7f_constEv
d.f_const();
// CHECK: call void @_ZN1A1fEv
(d).f();
// CHECK: call void @_ZN1A1fEv
(true, d).f();
// CHECK: call void @_ZN1D1gEv
(true, d).g();
// CHECK: call void @_ZN1A1fEv
xd.d.f();
// CHECK: call void @_ZN1A1fEv
XD().d.f();
// CHECK: call void @_ZN1A1fEv
D XD::*mp;
(xd.*mp).f();
// CHECK: call void @_ZN1D1gEv
(xd.*mp).g();
// Can't devirtualize this; we have no guarantee that p points to a D here,
// due to the "single object is considered to be an array of one element"
// rule.
// CHECK: call void %
p[0].f();
// FIXME: We can devirtualize this, by C++1z [expr.add]/6 (if the array
// element type and the pointee type are not similar, behavior is undefined).
// CHECK: call void %
p[1].f();
}
struct B {
virtual void f();
~B();
B h();
};
void f() {
// CHECK: call void @_ZN1B1fEv
B().f();
// CHECK: call void @_ZN1B1fEv
B().h().f();
}
namespace test2 {
struct foo {
virtual void f();
virtual ~foo();
};
struct bar : public foo {
virtual void f();
virtual ~bar();
};
void f(bar *b) {
// CHECK: call void @_ZN5test23foo1fEv
// CHECK: call %"struct.test2::foo"* @_ZN5test23fooD1Ev
b->foo::f();
b->foo::~foo();
}
}
namespace test3 {
// Test that we don't crash in this case.
struct B {
};
struct D : public B {
};
void f(D d) {
// CHECK-LABEL: define void @_ZN5test31fENS_1DE
d.B::~B();
}
}
namespace test4 {
struct Animal {
virtual void eat();
};
struct Fish : Animal {
virtual void eat();
};
struct Wrapper {
Fish fish;
};
extern Wrapper *p;
void test() {
// CHECK: call void @_ZN5test44Fish3eatEv
p->fish.eat();
}
}
// Do not devirtualize to pure virtual function calls.
namespace test5 {
struct X {
virtual void f() = 0;
};
struct Y {};
// CHECK-LABEL: define {{.*}} @_ZN5test51f
void f(Y &y, X Y::*p) {
// CHECK-NOT: call {{.*}} @_ZN5test51X1fEv
// CHECK: call void %
(y.*p).f();
};
struct Z final {
virtual void f() = 0;
};
// CHECK-LABEL: define {{.*}} @_ZN5test51g
void g(Z &z) {
// CHECK-NOT: call {{.*}} @_ZN5test51Z1fEv
// CHECK: call void %
z.f();
}
struct Q {
virtual void f() final = 0;
};
// CHECK-LABEL: define {{.*}} @_ZN5test51h
void h(Q &q) {
// CHECK-NOT: call {{.*}} @_ZN5test51Q1fEv
// CHECK: call void %
q.f();
}
}